Embodiments of the inventive concept relate to semiconductor devices and apparatuses that incorporate semiconductor devise. More particularly, embodiments of the inventive concept relate to charge pumps variously used in semiconductor devices. Charge pumps consistent with embodiments of the inventive concept reduce voltage ripple in an output voltage.
With continuous miniaturization of electronics and electrical devices, a multiplicity of functions has been integrated into different mobile devices. This multiplicity of functions often includes an ability to acquire still image and/or moving image information. In this context, many mobile devices include one or more image sensors. However, the function and performance of an image sensor included in a mobile device exercise great influence on the design and implementation of the mobile device. For example, technical improvements that reduce the power consumption and/or physical size of an image sensor chip are increasingly important.
Contemporary, semiconductor image sensor circuits (or “chips) that may be used to receive light (or more generally expressed, “to collect electromagnetic energy over a defined range of frequencies”) usually include a pixel array, as well as circuits controlling the response of pixel array elements to incident light and further controlling the output of resulting electrical signals. For example, image sensor chips usually include so-called “row driver(s)” and “readout circuit(s)”. In this context, an operating voltage supplied to a row driver may be significantly higher in level than other operating voltage(s) supplied to other circuits in an image sensor chip. In order to efficiently generate this type of higher level operating voltage, a so-called “charge pump” circuit may be used. The general use of charge pumps in different semiconductor applications is well understood, but charge pumps associated with an image sensor chip must not only operate with high reliability, but also provide an operating voltage with significantly low voltage ripple.